Why are there 60 seconds in a minute and 60 minutes in a hour?

Around 2400 BC, the ancient Sumerians, who used six as their mathematical base, divided the circle into 360 degrees, with each degree sub-divided into another 60 parts, and so on. The Romans called these units minute prima, or first small part, and secunda minuta, or second small part. This system was perfect for round clock faces, and that's why we use minutes and seconds as divisions of time.

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